[CompilerType] Simplify the interface a bit more..

[davide]

Summary

.. removing IsMeaninglessWithoutTypeResolution(). I'm fairly
confident this was introduced to support swift, where
static types [without dynamic counterpart] don't carry a lot
of value. Since then, the formatters and dynamic type resolution
has been rewritten, and we employ different solutions. This function
is unused here too, so let's get read of it.

rdar://problem/36377967

[alex]

I was marked as a review on this, but I suspect you intended to get some other Alex :-)

[davide]

In D65782#1615959, @alex wrote:

I was marked as a review on this, but I suspect you intended to get some other Alex :-)

yes, sorry. My bad.

lldb/include/lldb/Symbol/CompilerType.h

public:
   // Returns the value of the template argument and its type.
   llvm::Optional<IntegralTemplateArgument>
   GetIntegralTemplateArgument(size_t idx) const;
 
   CompilerType GetTypeForFormatters() const;
 
   LazyBool ShouldPrintAsOneLiner(ValueObject *valobj) const;
 
-  bool IsMeaninglessWithoutDynamicResolution() const;
-
   // Dumping types
 
 #ifndef NDEBUG
   /// Convenience LLVM-style dump method for use in the debugger only.
   /// Don't call this function from actual code.
   LLVM_DUMP_METHOD void dump() const;
 #endif
 

lldb/include/lldb/Symbol/TypeSystem.h

#endif
   virtual PersistentExpressionState *GetPersistentExpressionState() {
     return nullptr;
   }
 
   virtual CompilerType GetTypeForFormatters(void *type);
 
   virtual LazyBool ShouldPrintAsOneLiner(void *type, ValueObject *valobj);
 
-  // Type systems can have types that are placeholder types, which are meant to
-  // indicate the presence of a type, but offer no actual information about
-  // said types, and leave the burden of actually figuring type information out
-  // to dynamic type resolution. For instance a language with a generics
-  // system, can use placeholder types to indicate "type argument goes here",
-  // without promising uniqueness of the placeholder, nor attaching any
-  // actually idenfiable information to said placeholder. This API allows type
-  // systems to tell LLDB when such a type has been encountered In response,
-  // the debugger can react by not using this type as a cache entry in any
-  // type-specific way For instance, LLDB will currently not cache any
-  // formatters that are discovered on such a type as attributable to the
-  // meaningless type itself, instead preferring to use the dynamic type
-  virtual bool IsMeaninglessWithoutDynamicResolution(void *type);
-
 protected:
   const LLVMCastKind m_kind; // Support for llvm casting
   SymbolFile *m_sym_file;
 };
 
 class TypeSystemMap {
 public:
   TypeSystemMap();

lldb/source/DataFormatters/FormatManager.cpp

if (valobj.GetBitfieldBitSize() > 0) {
     StreamString sstring;
     sstring.Printf("%s:%d", type_name.AsCString(), valobj.GetBitfieldBitSize());
     ConstString bitfieldname(sstring.GetString());
     entries.push_back(
         {bitfieldname, 0, did_strip_ptr, did_strip_ref, did_strip_typedef});
     reason |= lldb_private::eFormatterChoiceCriterionStrippedBitField;
   }
 
-  if (!compiler_type.IsMeaninglessWithoutDynamicResolution()) {
-    entries.push_back(
-        {type_name, reason, did_strip_ptr, did_strip_ref, did_strip_typedef});
 
-    ConstString display_type_name(compiler_type.GetDisplayTypeName());
-    if (display_type_name != type_name)
-      entries.push_back({display_type_name, reason, did_strip_ptr,
-                         did_strip_ref, did_strip_typedef});
-  }
+    entries.push_back({display_type_name, reason, did_strip_ptr, did_strip_ref,
+                       did_strip_typedef});
 
   for (bool is_rvalue_ref = true, j = true;
        j && compiler_type.IsReferenceType(nullptr, &is_rvalue_ref); j = false) {
     CompilerType non_ref_type = compiler_type.GetNonReferenceType();
     GetPossibleMatches(
         valobj, non_ref_type,
         reason |
             lldb_private::eFormatterChoiceCriterionStrippedPointerReference,

 ConstString FormatManager::GetValidTypeName(ConstString type) {
   return ::GetValidTypeName_Impl(type);
 }
 
 ConstString FormatManager::GetTypeForCache(ValueObject &valobj,
                                            lldb::DynamicValueType use_dynamic) {
   ValueObjectSP valobj_sp = valobj.GetQualifiedRepresentationIfAvailable(
       use_dynamic, valobj.IsSynthetic());
-  if (valobj_sp && valobj_sp->GetCompilerType().IsValid()) {
-    if (!valobj_sp->GetCompilerType().IsMeaninglessWithoutDynamicResolution())
-      return valobj_sp->GetQualifiedTypeName();
-  }
+  if (valobj_sp && valobj_sp->GetCompilerType().IsValid())
   return ConstString();
 }
 
 std::vector<lldb::LanguageType>
 FormatManager::GetCandidateLanguages(ValueObject &valobj) {
   lldb::LanguageType lang_type = valobj.GetObjectRuntimeLanguage();
   return GetCandidateLanguages(lang_type);
 }

lldb/source/Symbol/CompilerType.cpp

 }
 
 LazyBool CompilerType::ShouldPrintAsOneLiner(ValueObject *valobj) const {
   if (IsValid())
     return m_type_system->ShouldPrintAsOneLiner(m_type, valobj);
   return eLazyBoolCalculate;
 }
 
-bool CompilerType::IsMeaninglessWithoutDynamicResolution() const {
-  if (IsValid())
-    return m_type_system->IsMeaninglessWithoutDynamicResolution(m_type);
-  return false;
-}
-
 // Get the index of the child of "clang_type" whose name matches. This function
 // doesn't descend into the children, but only looks one level deep and name
 // matches can include base class names.
 
 uint32_t
 CompilerType::GetIndexOfChildWithName(const char *name,
                                       bool omit_empty_base_classes) const {
   if (IsValid() && name && name[0]) {

lldb/source/Symbol/TypeSystem.cpp

TypeSystem::GetIntegralTemplateArgument(opaque_compiler_type_t type,
                                         size_t idx) {
   return llvm::None;
 }
 
 LazyBool TypeSystem::ShouldPrintAsOneLiner(void *type, ValueObject *valobj) {
   return eLazyBoolCalculate;
 }
 
-bool TypeSystem::IsMeaninglessWithoutDynamicResolution(void *type) {
-  return false;
-}
-
 ConstString TypeSystem::DeclGetMangledName(void *opaque_decl) {
   return ConstString();
 }
 
 CompilerDeclContext TypeSystem::DeclGetDeclContext(void *opaque_decl) {
   return CompilerDeclContext();
 }